Smooth Focus for USB Microscope

I love my DigiMicro USB Microscope! The only problem with it is that focusing it is pain. The little adjustment wheel is impossible to turn without moving the microscope. So I created this little add-on to make focusing a breeze. Now I really love my microscope.

The design of the bracket and worm was done with FreeCAD. The knob used John Sanford's Parametric Knurled Nut Knob ( http://www.thingiverse.com/thing:439239 ). I can post the source files if anyone wants them.